After cold start the brake system is weak to non existent. We have a slope of approximately 25-30 degrees and this caused us to go into our neighbors yard when the brakes only slowed the vehicle and could not bring it to a complete stop. We are currently working with our local dealership to get the problem fixed, however diagnosis is problematic due to the fact that it only occurs on a cold start and then becomes a non issue. Currently yates Buick in Goodyear AZ has been dismissive and unhelpful with this problem and Buick customer care line is equally unhelpful. I will update if I can find a mechanic that can diagnose the problem.

- Litchfield Park, AZ, USA

Off and on over the past 6 months, there was a loss of brakes directly after startup. After 30 seconds or so, the brakes would function normally. This car is normally garage kept. Walking to the car at night to leave, I noticed oil on the garage floor coming from under the car. After opening the hood, I noticed oil in the engine compartment coming from the top of the engine. After removing the plastic engine cover, I saw that the oil was coming from what I learned is the vaccum pump. There was a visible break in the pump housing. I went to my local dealership to inquire about getting this serviced under warranty. They started that this part is only covered under the bumper to bumper warranty and not powertrain warranty, even though the vacuum pump is directly mounted to and connected to the intake camshaft. My bumper to bumper warranty had expired 3 1/2 months or 219 miles prior, yet the car is still under the powertrain warranty. The dealership was unwilling to help and quoted me $104 for a new ac delco vacuum pump. I was able to order a new ac delco vacuum pump from rock auto for $43. After receiving the new pump, a mechanic friend was helping me to replace the pump. When the old one was removed, it was shown to have disintegrated. The inside of the part was in many pieces. The part that engages the camshaft was also broke into pieces and at this point I believe that several of those are now inside the engine. At this point I am going to take the old part to the dealership, along with photos of the engine and demand that this is now fixed under the powertrain warranty, as the powertrain is directly affected. Had this happened while driving, the loss of brakes could have been catastrophic.

- Valparaiso, IN, USA

Vaccum pump falls apart inside of engine. This causes brakes to not work as intended as there is no boost. Replaced old oem with new oem and within 2 months happend again. At start up and for about two minutes you have no brake assistance. Eventually you will have no brake assistance. Please be careful

- Tremonton, UT, USA

Caliper sliders locked causing brakes to over heat/ lock, and may cause fire.

- Schererville, IN, USA